This invention relates generally to the art of back cushions and more particularly to the art of a back cushion adapted to minimize unnatural curvature of the spinal section between the sacral and dorsal areas of the spine.
Many prior art devices have attempted to provide for increased comfort within the small of the back portion of a human being in the sitting position. Many such devices are described within prior patents.
One such spinal support is described in U.S. Pat. No. 1,667,626 to Epstein. The spinal support described therein comprises a cushion having a back engaging portion substantially of a constant curvature and comprises handles for suspending the spinal support in an appropriate position from the top of a chair back.
Another such pad for a chair or seat back is described in U.S. Pat. No. 1,937,920 to Smith. Smith describes a support which extends from the seat area behind the buttocks of the sitting person into the small of the back. The back area within the small of the back is engaged by a surface of substantially constant curvature. The pad is adapted to be inverted to accommodate various size persons with the pad being positioned and retained upon the chair seat.
Another such back rest is described in U.S. Pat. No. 1,975,586 to Law. The back rest described therein is intended for use within a moving vehicle, such as automobiles and trains. The pillow is adapted for the circulation of air so as to minimize the accumulation of heat between the pillow and the user. The back rest is generally elliptical and is useful as a head cushion as well as a back rest.
While many such back rests or supports have been available within the prior art, no back rest device has been totally satisfactory for the proper positioning of the spine so as to minimize tension and unnatural curvature which may be caused by excessively long periods within such a sitting position and vibrations which may accompany transportation in a moving vehicle.